In one aspect this invention relates to a method for reversibly desensitizing primary explosives so as to render them substantially incapable of detonation by shock or impact. Another aspect of this invention relates to a method for manufacturing explosive articles which contain primary explosives wherein the dangers normally attending the production of such articles due to shock sensitivity are substantially alleviated. In still a further aspect, the present invention relates to a method for packaging the explosive materials comprising primary explosives which provides for desensitization of the primary explosive in bulk quantities with the subsequent recapture of shock sensitivity when smaller discrete portions of the primary explosive have been packaged.
The term "primary explosive" as used herein refers to shock sensitive explosive compositions conventionally used as initial detonating agents for less sensitive explosive compositions. These primary explosives are more easily detonated by application of impact or friction than are non-impact sensitive explosives such as ammonium nitrate, TNT and cellulose nitrate, for example. Specifically, the method of the present invention is directed to the primary explosives such as silver fulminate (AgONC). Silver fulminate has been used in the past in the manufacture of fireworks and similar materials such as impact torpedo noisemakers. However, because of its high impact sensitivity, handling bulk quantities of silver fulminate has presented substantial explosion hazards in the past. One example of an application of silver fulminate is the pyrotechnic noisemaker set forth in U.S. Pat. No. 4,005,657 issued Feb. 1, 1977. The noisemaking device disclosed therein comprises a small amount of impact sensitive explosive particles produced from coating gravel or sand with silver fulminate employing a suitable adhesive such as a water soluble casein glue. While relatively small amounts of the explosive silver fulminate are present in each of the individual noisemaker devices, manufacturing such noisemakers on a commercial scale presents the problem of handling bulk quantities of silver fulminate. Thus, for example, if it is desired to produce explosive particles on a commercial scale comprising a silver fulminate admixture of sand, the handling of bulk quantities of silver fulminate will involve a fairly high degree of risk of accidental impact detonation of the explosive. Furthermore, while silver fulminate has the explosive properties necessary for use in commercial blasting caps and military munitions, the impact sensitivity of the material presents safety hazards which in most cases outweigh the desirability of employing this explosive in those types of operations.
Thus, a method by which silver fulminate could be desensitized while in a bulk quantity so as not to be subject to accidental impact detonation and then later resensitized to thereby recapture its excellent impact sensitivity and explosive properties once it has been packaged in smaller discrete quantities is desirable and would facilitate the use of silver fulminate in a wide variety of explosive applications.